1. Field of the Invention
The present invention relates generally to the field of security systems and more specifically to a gate alarm switch which is primarily configured for mechanical and electrical compatability with latch gates and the like of the type which use a latch bar, a catch and a cam retainer, the alarm switch of the present invention being configured to provide preferably an audible signal whenever the latch gate is not fully secure in a closed and locked position. The invention hereof is especially suitable for swimming pool-access gates to prevent or at least advise of an inadvertently opened latch gate which is otherwise intended to prevent a unauthorized entry by small children into a pool area.
1. Prior Art
The hazard and potentially catastrophic risk of a swimming pool to small children is unfortunately well known. The number of accidental drownings of small children in residential swimming pools is far too high. Even one such tragic incident in any community each summer is a disaster for the entire community. Accidental drownings of young children are not only a catastrophe for the families touched by such accidents, but they also constitute a significant and potentially costly risk of liability for the owner of the swimming pool. The remedy of course is to completely enclose the swimming pool with a fence which cannot be breached by small children. However, even such a fence must provide a convenient access to the swimming pool users, normally in the form of a latched gate or door built into the fence. The latch assemblies normally used on such latched gates are of the type which employ a latch bar and a catch operating in conjunction with a cam retainer and located high enough to prevent small children from gaining access to manually open such latch assemblies. However, in order for such latch assemblies to be effective to prevent the inadvertent access to small children to swimming pools and other dangers enclosed by fences, it is necessary, indeed it is critical, that such latch assemblies be securely closed in their locked position so that the gate or door cannot be opened without first manually releasing the cam retainer, allowing the latch bar to be removed from the catch upon opening of the door or gate. Without a securely closed latch assembly, even the smallest toddlers attracted to a swimming pool or other potential hazard, can readily open such a gate without the knowledge of any nearby adult, and thus lead to a tragic result.
There have been attempts to commercialize devices designed to prevent such tragedies. By way of example, one manufacturer offers a motion alert system wherein a transmitter is mounted on the gate and generates a radio frequency signal to a remotely positioned receiver in response to motion of the gate. Unfortunately, such sophisticated systems tend to be expensive, a significant factor for discouraging their use. In addition, a motion detector device only operates to alert the homeowner of a door being opened when it is in motion and thus in the process of actually being opened. If no one is within hearing distance of the alarm when a child actually opens such a door or gate, such an alarm system is useless for the purpose herein above described. A much more effective alarm system for use with latch gates normally employed to provide access to enclosed pool areas and the like would be an alarm system which alerts nearby adults each time a latch gate is not firmly secured in its locked position. Such a device would be especially effective for latch assemblies of the type using cam retainers because such cam retainers do not always function properly, even when a visual inspection of the latch gate from any but the closest distances would fail to reveal that the latch assembly is not fully secured. The prior art is replete with a variety of different manually operated switches which are or can be designed, to interface electrically with an alarm system However, none of such prior art switch devices known to the applicant herein, is specifically designed for use in a latch gate configuration for assuring with a high degree of certainty that a latch assembly employed therein is securely closed.
The prior art known to the applicant includes the following U.S. Pat. Nos.
3,266,029 Callahan PA1 4,194,193 McDonough PA1 4,284,980 Hoinski PA1 4,284,982 Downey PA1 4,376,276 Barta PA1 4,686,504 German PA1 4,688,023 McGill et al PA1 4,691,195 Sigelman et al PA1 4,721,946 Zunkel PA1 4,808,974 Cantley PA1 4,843,374 Sansky PA1 4,912,456 Mickel
U.S. Pat. No. 4,688,023 to McGill is directed to a container having a child safety device and alarm. The alarm has a case or housing with transducer, a slide switch for enabling, an internal battery, and an alarm lever arm that operates an internal switch for sounding the alarm. The alarm system is disposed so that the lever arm is held by the device cover, latch or the like.
U.S. Pat. No. 4,376,276 to Barta is directed to a door alarm with flexible switch actuator. The self-contained alarm has a housing, cover, horn, battery, and operating switch with an arm that extends outside the housing with a resilient extension. The housing mounted to a stationary object is positioned so that the arm is engaged by the door when it is opened.
U.S. Pat. No. 4,808,974 to Cantley is directed to a self-contained portable door alarm. The alarm for mounting on a door with frame has a housing with an audible alarm, a mounting bracket, internal battery, and a set switch. Projecting from the top of the housing is alarm actuating lever biased to turn the alarm on. When properly mounted on the door, the frame holds the actuating lever against its bias, thus keeping the alarm off. A lock-on circuit can be provided to maintain the alarm on the position once activated.
U.S Pat. No. 3,266,029 to Callahan is directed to a self-container burglar alarm system. The system has a casing which encloses a horn, batteries, and a motor drive system for a time delay. A control arm assembly projects outside the casing with an arm for engaging the door frame and maintaining the horn in the off condition. When the door is opened, a biasing spring moves the arm so that a contact energizes the horn after an appropriate time delay from the motor cam circuitry.
U.S. Pat. No. 4,912,456 to Mickel is directed to a door latch alarm. The door latch alarm has a housing mounted on the inside and outside of the door supporting door handle. The upper compartment of the housing contains a battery, bell, deactivate switch, and contact fingers. The latch bolt has a link supporting the contact that engages the contact fingers when the latch is moved rearward by operating the handle.
There is therefore a long felt and unresolved need for a relatively low cost and relatively simple, but yet relatively fool-activated system for assuring secure closure of a latch gate of the type described hereinafter.